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BUG: KASAN: use-after-free in inet_shutdown+0x2d3/0x350 net/ipv4/af_inet.c:816
Read of size 4 at addr ffff888099fe7980 by task syz-executor.0/13326

CPU: 0 PID: 13326 Comm: syz-executor.0 Not tainted 4.14.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
 inet_shutdown+0x2d3/0x350 net/ipv4/af_inet.c:816
 pppol2tp_session_close+0xa0/0xe0 net/l2tp/l2tp_ppp.c:441
 l2tp_tunnel_closeall+0x243/0x380 net/l2tp/l2tp_core.c:1340
 l2tp_udp_encap_destroy+0x96/0x100 net/l2tp/l2tp_core.c:1366
 udpv6_destroy_sock+0xb3/0xd0 net/ipv6/udp.c:1444
 sk_common_release+0x6b/0x310 net/core/sock.c:2989
 udp_lib_close+0x16/0x20 include/net/udp.h:203
 inet_release+0xec/0x1c0 net/ipv4/af_inet.c:425
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:450
 __sock_release+0xce/0x2b0 net/socket.c:602
 sock_close+0x1b/0x30 net/socket.c:1139
 __fput+0x275/0x7a0 fs/file_table.c:210
 ____fput+0x16/0x20 fs/file_table.c:244
 task_work_run+0x114/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4144a1
RSP: 002b:00007ffcd57dd2b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004144a1
RDX: 0000000000000000 RSI: 0000000000000081 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffffffffff
R10: 00000000007609e0 R11: 0000000000000293 R12: 000000000075bfc8
R13: 0000000000000002 R14: 00000000007609f0 R15: 000000000075bfd4

Allocated by task 13330:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x780 mm/slab.c:3552
 sock_alloc_inode+0x1d/0x260 net/socket.c:251
 alloc_inode+0x64/0x180 fs/inode.c:209
 new_inode_pseudo+0x19/0xf0 fs/inode.c:891
 sock_alloc+0x41/0x280 net/socket.c:569
 __sock_create+0x8f/0x620 net/socket.c:1239
 sock_create net/socket.c:1315 [inline]
 SYSC_socket net/socket.c:1345 [inline]
 SyS_socket+0xd3/0x170 net/socket.c:1325
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 13330:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x83/0x2b0 mm/slab.c:3758
 sock_destroy_inode+0x54/0x60 net/socket.c:281
 destroy_inode+0xc2/0x120 fs/inode.c:266
 evict+0x3e6/0x630 fs/inode.c:571
 iput_final fs/inode.c:1516 [inline]
 iput fs/inode.c:1543 [inline]
 iput+0x471/0x900 fs/inode.c:1528
 dentry_unlink_inode+0x286/0x340 fs/dcache.c:387
 __dentry_kill+0x32e/0x580 fs/dcache.c:591
 dentry_kill fs/dcache.c:632 [inline]
 dput.part.0+0x59f/0x750 fs/dcache.c:847
 dput+0x20/0x30 fs/dcache.c:811
 __fput+0x45f/0x7a0 fs/file_table.c:228
 ____fput+0x16/0x20 fs/file_table.c:244
 task_work_run+0x114/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff888099fe7980
 which belongs to the cache sock_inode_cache of size 992
The buggy address is located 0 bytes inside of
 992-byte region [ffff888099fe7980, ffff888099fe7d60)
The buggy address belongs to the page:
page:ffffea000267f9c0 count:1 mapcount:0 mapping:ffff888099fe7080 index:0xffff888099fe7ffd
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff888099fe7080 ffff888099fe7ffd 0000000100000003
raw: ffffea00023c41e0 ffffea000267f9a0 ffff8880a9e19780 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888099fe7880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888099fe7900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888099fe7980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888099fe7a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888099fe7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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